Work is continuing on the covalent affinity chromatography of acetyl-cholinesterase based upon the "nerve gas" reaction and the reactivation of the phosphorylated enzyme by suitable nucleophiles. Enzyme will be purified from various sources such as the human eye, and the kinetic and molecular features of the enzyme will be examined. The aggregation of eel enzyme will be studied as well as the structure of the unaggregated forms.